Usually, a printer connected to a network is shared by a plurality of user terminals. In this environment, the situation might occur that the printed matter of a user is seen by another user, or that the printed matter is erroneously taken away by another user. Such a situation is problematic in case of printing which is to be done with security afforded, for example, printing of secret or private information that ought not to be seen by any other user.
As a method for solving the above problem, the following has been known: First, a printer driver which can transmit a password to a printer simultaneously with the transmission of print data is prepared on the side of the user's computer system. Besides, the printer or printer server is furnished with means for identifying the password transmitted from the user's computer. Also, the password is registered on the side of the printer or printer server beforehand. In the case where the user prints the information not desired to be seen by another user, he/she transmits the print data and the password from his/her own computer to the printer. In the printer, the password is collated with a group of passwords registered beforehand, so as to confirm the user. Herein, the print data is not immediately printed, but it is once stored in a memory. The user goes to a place where the printer is installed, and inputs his/her password directly to the printer. In response to the input of the password, the printer prints the print data stored in the memory. In this way, the user can reliably obtain printed matter which is desired to be kept confidential, and he/she can avoid the problem that the contents of the printed matter are seen by another user. Such methods are described in, for example, Japanese Patent Publication Nos. H8-39898, H8-83153 and H9-65148.
The above conventional printing method which is implemented with security afforded, has a problem that the dedicated printer driver is required to handle the extra information or password, and it would take time and cost to install it. Besides, the conventional printing method has another problem that individual registration of passwords in the printer is required, which would complicate a setting procedure at a stage prior to printing. By way of example, when a portable personal computer carried into an office from outside is connected to a network to direct a print operation from the portable personal computer, the above printing method requires a troublesome procedure to set a password in the printer beforehand.